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Stari

The document provides design details for a two-way slab and dog-legged stair. For the slab, calculations are shown for load, moment, required reinforcement area and spacing. The slab design meets requirements for depth, deflection and shear. For the stair, material properties and load calculations are given for the waist slab and landing. Moment calculations determine the maximum moment and required depth. Reinforcement details for the main and distribution bars are then provided.

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Bikal Bastakoti
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100 views28 pages

Stari

The document provides design details for a two-way slab and dog-legged stair. For the slab, calculations are shown for load, moment, required reinforcement area and spacing. The slab design meets requirements for depth, deflection and shear. For the stair, material properties and load calculations are given for the waist slab and landing. Moment calculations determine the maximum moment and required depth. Reinforcement details for the main and distribution bars are then provided.

Uploaded by

Bikal Bastakoti
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as XLSX, PDF, TXT or read online on Scribd
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Slab

Cantilever 7
Simple Supported 20
Continuous 26
Both 23

Depth >300 275 250 225 200 175 150>


K 1 1.05 1.1 1.15 1.2 1.25 1.3

Grade (Concrete) 20 25 30 35 40
Bond Stress 1.2 1.4 1.5 1.7 1.9
Two Way Slab
Design Data

fck 20 N/mm2
fy 500 N/mm2

Slab Dimension
Length of Short span (lx) 3.580 m (c/c distance)
Length of Longer span (ly) 4.416 m (c/c distance)
Width of Supporting Beam 230.000 mm
Clear Cover to main Reinforcement 15.000 mm

Assume,
Diamter of the Reinforcement Steel 8.000 mm

Calculations

Assume,
Thickness of Slab 125.000 mm
Effective Depth (deff) 106.000 mm

For Effective Span,


Length of Short span (lx) 3.580 m or 3.456 m (Whichever is less)
Length of Longer span (ly) 4.416 m or 4.292 m (Whichever is less)

𝑙𝑦/𝑙𝑥
1.242 <2

: therefore a Two way slab

Hence we design the slab as Two way Slab

Load Calculations

Dead Load of Slab 3.125 KN/m2


Floor Finish Load on Slab 1.200 KN/m2

Total Dead Load 4.325 KN/m2

Live Load on Slab 2.000 KN/m2


Factored Design Load 9.488 KN/m2

Support Conditions

We have,
Two Adjacent Edges are Discontinuous From Table26:
(IS 456:2000)
Short Span Coefficient for (ly/lx)
for, Negative moment 𝛼x 0.0621
for, Positive moment 𝛼y 0.0467

Long Span Coefficient for (ly/lx)


for, Negative moment 𝛼x 0.047
for, Positive moment 𝛼y 0.035
s
Moment Calculation

Maximum Bending Moment per unit width From Annex D.1.1


Mx 𝛼x . w. (lx)²
My 𝛼y . w. (lx)²

Ast req
Mu (KNm) pt (%) Spacing
(mm2 ) (mm)
For Short Span
At mid span 5.292 112.460 0.090 446.963
At support 7.037 153.080 0.122 328.361

For Long Span


At mid span 3.966 85.000 0.068 591.359
At support 5.326 114.980 0.092 437.167

Checking for Depth


Mmax : 7.037 KNm

(𝑑)=√(𝑀𝑚𝑎𝑥/ For Fe500


(0.133∗𝑓𝑐𝑘∗𝑏))

d: 51.435 mm Ok

Also We have,

Ast min (mm2 ) (0.12/100)bD


150.000 mm2
Reinforcement Details

Fro Short Span provide,


8@ 150mm c/c at Midspan and Support Ast pro : 335.103 mm2

Fro Long Span provide,


8@ 150mm c/c at Midspan and Support Ast pro : 335.103 mm2

Check:
For Deflection

𝐿𝑥/𝑑≤αβγδλ

α: 26 Slab Type: Continuous


β 1 Span less than 10m
γ 1 No Compression Reinforcement
δ 1 No Flanged Section

fro λ
Percentage of Tension Reinforcement 0.316 %
For Modification Factor

(𝐴𝑟𝑒𝑎 𝑜𝑓 𝑆𝑡𝑒𝑒𝑙 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑)/(𝐴𝑟𝑒𝑎 𝑜𝑓 𝑆𝑡𝑒𝑒𝑙 𝑃𝑟𝑜𝑣𝑖𝑑𝑒𝑑)


fs= 0.58. fy

fs 132.476 Cl. 23.2.1; Fig 4: (IS


M.F (λ) 2 456:2000)

𝑙/𝑑
max
52.000

𝑙/𝑑
provided
32.604
Safe
As l/d max > l/d provided

Hence, Beam is safe in deflection


Check:
For Shear

Shear Force per m strips (V) : (W*lx/2)


16.394 KN/m
Shear Stress (τv) : (V/bd) Cl.40.1:
0.155 N/mm2 (IS 456:2000)
Also;
Percentage of Tension Reinforcement 0.316 Cl.40.2.1.1:
k 1.3 (IS 456:2000)
(τc) 0.478 N/mm2 From Table19:
>τv Safe (IS 456:2000)
Since (τc) >(τv), Safe in Shear

Hence, Beam is safe in Shear

Check:
For Development Length

Ld=Ø𝜎𝑠/ (1.6 for Deformed bars) Cl.26.2.1.:


1.6𝑥4𝑥𝜏 :
453.125 mm (IS 456:2000)
Also
𝑀/𝑉
Ld ≤ 1.3 +Lo

(𝑓𝑦.𝐴𝑠𝑡
M =0.87. fy. Ast..(1/2).(d- )/(𝑓𝑐𝑘∗𝑏∗2)
)
M: 7420504.891 Nmm
V: 16394.400 N
Lo: 80.000 mm
so,
Ld: 668.412 mm
> 453.125
Safe
Design of Dog Legged Stair

Material Properties

fck 20 N/mm2
fy 415 N/mm2
Cover 20 mm
Diameter of Main Bars 12 mm
Diameter of Distribution Bars 12 mm

Tread 0.250 m
Riser 0.176 m
Thickness of Waist Slab 0.150 m
Width of Step 1.000 m
Width of Landing 1.028 m
Thickness of Landing Slab 0.150 m
Span of Landing A 1.066 m
Span of First Flight 1.778 m
Span of Landing B 1.371 m
Total Span 4.215 m deff = 0.130

A B
Load on Waist Slab
Area of Slab 0.046 m2
Area of Step 0.022 m2
Total Area 0.068 m2
DL per m 1.697 KN/m
DL 6.786 KN/m2
FF 1.500 KN/m2
LL 3.000 KN/m2
Total Load per sq.m 11.286 KN/m2
Facotored Load 16.929 KN/m2
Load per m 16.929 KN/m2

Load on Landing
Self Weight of Slab 3.750 KN/m2
FF 1.200 KN/m2
LL 3.000 KN/m2
Load per sq.m 7.950 KN/m2
Factored Load 11.925 KN/m2
Load per m 12.259 KN/m

Calculation of Moments

Total Load 59.975 KN


Reaction at B 29.687 KN
Reaction at A 30.288 KN
Point of Zero Shear 2.083 m From A
Mmax 29.016 KNm

Depth

Effective Depth form Moment


Mmax = 0.133Fck.bd2
dreq : 104.442 <d provided
130.000 mm
we have.
(𝑓𝑦. 𝐴𝑠𝑡)/(𝑓𝑐𝑘.𝑏.𝑑))
Mmax = 0.87 .fy.Ast.d.(1-

Area of steel required (Ast) : 564.760 m2

For Main Steel


Required
Area of steel required (Ast) : 564.760 mm2
Diameter of Steel 12.000 mm
Spacing : 200.257 mm

Provided
Area of steel (Ast) : 753.982 mm2
Diameter of Steel 12.000 mm
Spacing : 150.000 mm
Check:
For Minimum Reinforcement
Ast min (mm2 ): (0.12/100)bD
156.000 mm2

for Distribution Bars


Required
Area of steel required (Ast) : 156.000 mm2
Diameter of Steel 12.000 mm
Spacing : 724.983 mm

Provided
Area of steel (Ast) : 753.982 mm2
Diameter of Steel 12.000 mm
Spacing : 150.000 mm

Check:
for Shear

Shear Force (Vu) 30.288 KN

Nominal Shear Force (τv) (V/bd) Cl.40.1:(IS 456:2000)


0.233 N/mm2
Percentage of Tensile Reinforcement (pt) 0.580 %
Cl.40.2.1.1: (IS 456:2000)
k 1.300
Design Shear Strength (τc) 0.628 N/mm2 From Table19:(IS 456:2000)
Check Safe
Since (τc) > τv, Safe in Shear

Check:
for Deflection Fs= 217.221
𝐿𝑥/𝑑≤αβγδλ

α: 26 Slab Type: Continuous


β 1 Span less than 10m
γ 1 No Compression Reinforcement
δ 1 No Flanged Section

fro λ
Percentage of Tension Reinforcement : 0.580 %
For Modification Factor
(𝐴𝑟𝑒𝑎 𝑜𝑓 𝑆𝑡𝑒𝑒𝑙 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑)/(𝐴𝑟𝑒𝑎 𝑜𝑓 𝑆𝑡𝑒𝑒𝑙 𝑃𝑟𝑜𝑣𝑖𝑑𝑒𝑑)
fs= 0.58. fy

fs 217.221 Cl. 23.2.1; Fig 4:


M.F (λ) 1.3 (IS 456:2000)

𝑙/𝑑
max
33.800

𝑙/𝑑
provided
32.423
Safe
As l/d max > l/d provided

Check:
For Development Length

Ld=Ø𝜎𝑠/ (1.6 for Deformed bars)


1.6𝑥4𝑥𝜏 :
0.000 mm
We have Ld: 57 Ø
𝑀/𝑉 Cl.26.2.:
Ld ≤ 1.3 +Lo
(IS 456:2000)

M: 38.737 KNm
V: 30.288 KN
Lo: 120.000 mm
Ø: 31.473 mm
> 12.000 mm
Safe
Therefore, the design is safe for providing development length
Design of Isolated Footing
without Eccentricity

Design Data

Column no :
Load Case:
Concrete Grade: 20
Steel grade (fe) 415
Design Axial Load 655.22
Ultimate Load 982.83 KN
My 0 KNm
Mz 0 KNm
Column size (l) 305 mm
Column size(b) 305 mm
Soil Bearing Capacity 150 KN/m2
Design Factor 1.5

Footing Size Design

Design Load 655.22 KN


App. Self weight 65.52 KN
Total Weight 720.74 KN
Area of Footing 4.80 m2
Ratio of Footing 1
Size of Footing (L) 2.2 m
Size of Footing (B) 2.2 m

We consider
Size of Footing (L) 2.2
Size of Footing (B) 2.2
Projection (l1) 0.95 m
Projection (b1) 0.95 m

Upward Soil Pressure from Soil (BCS) 223.37045455 KN/m2

Maximum Bending Moment

BM at Y-Y face 220.59 KNm

BM at X-X face 220.59 KNm


Mu 220.59 KNm

Depth of Footing

For Fe415
d 190.60 mm

Increasing the depth by 1.5 times to resist shear


d 381.20 mm
We consider;
d 450 mm

Calculation of Reinforcement

BM 220.5854438
BM= 0.87 fyAst.(d-(Ast.fy/fck.B)
Using
For Longer Direction
Ast 1398.64 mm2
Diameter of Bars 12 mm
Spacing 177.90 < 300 mm
Safe

For Shorter Direction


Ast 1398.64
Diameter of Bars 12 mm
Spacing 177.90 < 300 mm
Safe
Provide
For Longer Direction Provide Ø 12 170 c/c
Ast 1463.6125774 mm 2

For Shorter Direction Provide Ø 12 170 c/c


Ast 1463.6125774 mm 2

Check
One Way Shear
Vy-y 244.48 KN
Vx-x 244.48 KN
Vu 244.48 KN
Tv 0.25 < 0.28 N/mm2
Safe From (Table19,IS 456:2000)
From(40.2.1.1,IS 456:2000)
Two Way Shear

Vu 953.79 KN
Tv 0.70 N/mm2
Tc 1.12 N/mm2
Safe

For Development Length

From Column
Fck 20 N/mm2
Fy 500 N/mm2
Diamter of Bar 25 mm

Ld 1416.015625 mm

Available length 1855 mm

No Bend

For Flexure
d 450

k: 1
1.05
1.1
1.2
1.25

k: 1

T 1.2
k: 1.6
Design of Isolated Footing
with Eccentricity

Design Data

Column no :
Load Case:
Concrete Grade: 20
Steel grade (fe) 415
Design Axial Load 655.22
Ultimate Load 982.83 KN
My 0 KNm
Mz 0 KNm
Column size (l) 305 mm
Column size(b) 305 mm
Soil Bearing Capacity 150 KN/m2
Design Factor 1.5

Footing Size Design

Design Load 655.22 KN


App. Self weight 65.52 KN
Total Weight 720.74 KN
Area of Footing 4.80 m2
Ratio of Footing 1
Size of Footing (L) 2.2 m
Size of Footing (B) 2.2 m

We consider
Size of Footing (L) 2.2
Size of Footing (B) 2.2
Projection (l1) 0.95 m
Projection (b1) 0.95 m

Upward Soil Pressure from Soil (BCS) 223.37045455 KN/m2

Maximum Bending Moment

BM at Y-Y face 220.59 KNm

BM at X-X face 220.59 KNm


Mu 220.59 KNm

Depth of Footing

For Fe415
d 190.60 mm

Increasing the depth by 1.5 times to resist shear


d 381.20 mm
We consider;
d 450 mm

Calculation of Reinforcement

BM 220.5854438
BM= 0.87 fyAst.(d-(Ast.fy/fck.B)
Using
For Longer Direction
Ast 1398.64 mm2
Diameter of Bars 12 mm
Spacing 177.90 < 300 mm
Safe

For Shorter Direction


Ast 1398.64
Diameter of Bars 12 mm
Spacing 177.90 < 300 mm
Safe
Provide
For Longer Direction Provide Ø 12 170 c/c
Ast 1463.6125774 mm 2

For Shorter Direction Provide Ø 12 170 c/c


Ast 1463.6125774 mm 2

Check
One Way Shear
Vy-y 244.48 KN
Vx-x 244.48 KN
Vu 244.48 KN
Tv 0.25 < 0.28 N/mm2
Safe From (Table19,IS 456:2000)
From(40.2.1.1,IS 456:2000)
Two Way Shear

Vu 953.79 KN
Tv 0.70 N/mm2
Tc 1.12 N/mm2
Safe

For Development Length

From Column
Fck 20 N/mm2
Fy 500 N/mm2
Diamter of Bar 25 mm

Ld 1416.015625 mm

Available length 1855 mm

No Bend

For Flexure
d 450

k: 1
1.05
1.1
1.2
1.25

k: 1

T 1.2
k: 1.6
Design of Isolated Footing
without Eccentricity

Design Data

Column no :
Load Case:
Concrete Grade: 20
Steel grade (fe) 415
Design Axial Load 400
Ultimate Load 600 KN
My 0 KNm
Mz 0 KNm
Column size (l) 305 mm
Column size(b) 305 mm
Soil Bearing Capacity 150 KN/m2
Design Factor 1.5

Footing Size Design

Design Load 400.00 KN


App. Self weight 40.00 KN
Total Weight 440.00 KN
Area of Footing 2.93 m2
Ratio of Footing 1
Size of Footing (L) 1.7 m
Size of Footing (B) 1.7 m

We consider
Size of Footing (L) 1.8
Size of Footing (B) 1.8
Projection (l1) 0.75 m
Projection (b1) 0.75 m

Upward Soil Pressure from Soil (BCS) 203.7037037 KN/m2

Maximum Bending Moment

BM at Y-Y face 102.44 KNm

BM at X-X face 102.44 KNm


Mu 102.44 KNm

Depth of Footing

For Fe415
d 143.60 mm

Increasing the depth by 1.5 times to resist shear


d 287.19 mm
We consider;
d 400 mm

Calculation of Reinforcement

BM 102.43864583
BM= 0.87 fyAst.(d-(Ast.fy/fck.B)
Using
For Longer Direction
Ast 724.37 mm2
Diameter of Bars 12 mm
Spacing 281.04 < 300 mm
Safe

For Shorter Direction


Ast 724.37
Diameter of Bars 12 mm
Spacing 281.04 < 300 mm
Safe
Provide
For Longer Direction Provide Ø 12 270 c/c
Ast 753.98223686 mm 2

For Shorter Direction Provide Ø 12 270 c/c


Ast 753.98223686 mm 2

Check
One Way Shear
Vy-y 127.42 KN
Vx-x 120.34 KN
Vu 127.42 KN p 0.10471975511966
Tv 0.18 < 0.28 N/mm 2

Safe From (Table19,IS 456:2000)


From(40.2.1.1,IS 456:2000)
Two Way Shear

Vu 558.75 KN
Tv 0.50 N/mm2
Tc 1.12 N/mm2
Safe

For Development Length

From Column
Fck 20 N/mm2
Fy 500 N/mm2
Diamter of Bar 25 mm

Ld 1416.015625 mm

Available length 1855 mm

Okay

For Flexure
d 400

k: 1
1.05
1.1
1.2
1.25

k: 1

T 1.2
k: 1.6
Design of Dog Legged Stair

Material Properties

fck 20 N/mm2
fy 415 N/mm2
Cover 20 mm
Diameter o 12 mm
Diameter of 12 mm

Tread 0.250 m
Riser 0.176 m
Thickness o 0.150 m 150 mm
Width of S 1.000 m
Width of L 1.028 m
Thickness 0.150 m
Span of La 1.066 m
Span of Fir 1.778 m
Span of La 1.371 m
Total Span 4.215 m deff 0.130

A B
Load on Waist Slab
Area of Sla 0.046 m2
Area of Ste 0.022 m2
Total Area 0.068 m2
DL per m 1.697 KN/m
DL 6.786 KN/m2
FF 1.500 KN/m2
LL 3.000 KN/m2
Total Load 11.286 KN/m2
Facotored 16.929 KN/m2
Load per m 16.929 KN/m2

Load on Landing
Self Weight 3.750 KN/m2
FF 1.200 KN/m2
LL 3.000 KN/m2
Load per s 7.950 KN/m2
Factored L 11.925 KN/m2
Load per m 12.259 KN/m

Calculation of Moments

Total Load 59.975 KN


Reaction a 29.687 KN
Reaction a 30.288 KN
Point of Ze 2.083 m From A
Mmax 29.016 KNm

Depth

Effective Depth form Moment


Mmax = 0.133Fck.bd2
dreq : 104.442 <d provided
130.000 mm
we have.
Mmax = 0.87 .fy.Ast.d.(1- (𝑓𝑦. 𝐴𝑠𝑡)/(𝑓𝑐𝑘.𝑏.𝑑))
Area of ste 564.760 m2

For Main Steel


Required
Area of ste 564.760 mm2
Diameter of 12.000 mm
Spacing : 200.257 mm

Provided
Area of ste 753.982 mm2
Diameter o 12.000 mm
Spacing : 150.000 mm

Check:
For Minimum Reinforcement
Ast min
(mm2 ): (0.12/100)bD
156.000 mm2

for Distribution Bars


Required
Area of ste 156.000 mm2
Diameter of 12.000 mm
Spacing : 724.983 mm

Provided
Area of ste 753.982 mm2
Diameter o 12.000 mm
Spacing : 150.000 mm

Check:
for Shear

Shear Forc 30.288 KN


Nominal Sh(V/bd) Cl.40.1:
0.233 N/mm 2 (IS 456:2000)
Percentage 0.580 % Cl.40.2.1.1:
k 1.250 (IS 456:2000)
Design Shea 0.628 N/mm2 From Table19:
Check Safe (IS 456:2000)
Since (τc) > τv, Safe in Shear

Check:
for Deflection Fs= 217.221
𝐿𝑥/𝑑≤αβγδλ
α: 26 Slab Type: Continuous
β 1 Span less than 10m
γ 1 No Compression Reinforcement
δ 1 No Flanged Section

fro λ
Percentage 0.580 %
For Modification Factor
fs= 0.58. fy
(𝐴𝑟𝑒𝑎 𝑜𝑓 𝑆𝑡𝑒𝑒𝑙 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑)/(𝐴𝑟𝑒𝑎 𝑜𝑓 𝑆𝑡𝑒𝑒𝑙 𝑃𝑟𝑜𝑣𝑖𝑑𝑒𝑑)
fs 217.221 Cl. 23.2.1; Fig 4:
M.F (λ) 1.3 (IS 456:2000)

𝑙/𝑑
max
33.800
max
33.800

𝑙/𝑑
provided
32.423
Safe
As l/d max > l/d provided

Check:
For Development Length

Ld=Ø𝜎𝑠/ (1.6 for Deformed bars)


:
1.6𝑥4𝑥𝜏
0.000 mm
We have Ld: 57 Ø
𝑀/𝑉 Cl.26.2.:
Ld ≤ 1.3 +Lo
(IS 456:2000)

M: 38.737 KNm
V: 30.288 KN
Lo: 120.000 mm
so, mm
Ø: 31.473 mm
> 12.000 mm
Safe
Therefore, the design is safe for providing development length

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